// C04:4.24:choices.cpp -- array variations
#include <iostream>
#include <vector>    // STL C++98
#include <array>     // C++11

int main(void)
{
	using namespace std;
	// C, original C++
	double a1[4] = {1.2, 2.4, 3.6, 4.8};
	// C++98 STL
	vector<double> a2(4);    // create vector with 4 elements
	// no simple way to initialize in C98
	a2[0] = 1.0 / 3.0;
	a2[1] = 1.0 / 5.0;
	a2[2] = 1.0 / 7.0;
	a2[3] = 1.0 / 9.0;
    // C++11 -- create and initialize array object
	array<double, 4> a3 = {3.14, 2.72, 1.62, 1.41};
	array<double, 4> a4;
	a4 = a3;    // valid for array object of same size
	// use array notation
	cout << "a1[2]: " << a1[2] << " at " << &a1[2] << endl;
	cout << "a2[2]: " << a2[2] << " at " << &a2[2] << endl;
	cout << "a3[2]: " << a3[2] << " at " << &a3[2] << endl;
	cout << "a4[2]: " << a4[2] << " at " << &a4[2] << endl;
	// misdeed
	a1[-2] = 20.2;
	cout << "a1[-2]: " << a1[-2] << " at " << &a1[-2] << endl;
	cout << "a3[2]: " << a3[2] << " at " << &a3[2] << endl;
	cout << "a4[2]: " << a4[2] << " at " << &a4[2] << endl;
}
